[PATCH v2] gpio: ath79: Fix potential NULL dereference in ath79_gpio_probe()

[PATCH v2] gpio: ath79: Fix potential NULL dereference in ath79_gpio_probe()

[Alban Bedel]

From: Wei Yongjun <weiyongjun1@huawei.com>

platform_get_resource() may return NULL, add proper
check to avoid potential NULL dereferencing.

This is detected by Coccinelle semantic patch.

@@
expression pdev, res, n, t, e, e1, e2;
@@

res = platform_get_resource(pdev, t, n);
+ if (!res)
+   return -EINVAL;
... when != res == NULL
e = devm_ioremap(e1, res->start, e2);

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
[albeu@free.fr: Fixed patch to apply on current tree]
Signed-off-by: Alban Bedel <albeu@free.fr>
---
 drivers/gpio/gpio-ath79.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpio/gpio-ath79.c b/drivers/gpio/gpio-ath79.c
index 3ae7c18..684e9d6 100644
--- a/drivers/gpio/gpio-ath79.c
+++ b/drivers/gpio/gpio-ath79.c
@@ -258,6 +258,8 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 	ctrl->base = devm_ioremap_nocache(
 		&pdev->dev, res->start, resource_size(res));
 	if (!ctrl->base)
-- 
2.7.4

Re: [PATCH v2] gpio: ath79: Fix potential NULL dereference in ath79_gpio_probe()

[Linus Walleij]

On Sun, Mar 25, 2018 at 12:40 AM, Alban Bedel <albeu@free.fr> wrote:

> From: Wei Yongjun <weiyongjun1@huawei.com>
>
> platform_get_resource() may return NULL, add proper
> check to avoid potential NULL dereferencing.
>
> This is detected by Coccinelle semantic patch.
>
> @@
> expression pdev, res, n, t, e, e1, e2;
> @@
>
> res = platform_get_resource(pdev, t, n);
> + if (!res)
> +   return -EINVAL;
> ... when != res == NULL
> e = devm_ioremap(e1, res->start, e2);
>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> [albeu@free.fr: Fixed patch to apply on current tree]
> Signed-off-by: Alban Bedel <albeu@free.fr>

Patch applied.

Yours,
Linus Walleij